import json
import logging
import os
import pathlib
import re
from copy import deepcopy
from pathlib import Path
from packaging import version

import torch
import transformers

from .model import CLAP, convert_weights_to_fp16
from .openai import load_openai_model
from .pretrained import get_pretrained_url, download_pretrained
from .transform import image_transform

_MODEL_CONFIG_PATHS = [Path(__file__).parent / f"model_configs/"]
_MODEL_CONFIGS = {}  # directory (model_name: config) of model architecture configs


def _natural_key(string_):
    return [int(s) if s.isdigit() else s for s in re.split(r"(\d+)", string_.lower())]


def _rescan_model_configs():
    global _MODEL_CONFIGS

    config_ext = (".json",)
    config_files = []
    for config_path in _MODEL_CONFIG_PATHS:
        if config_path.is_file() and config_path.suffix in config_ext:
            config_files.append(config_path)
        elif config_path.is_dir():
            for ext in config_ext:
                config_files.extend(config_path.glob(f"*{ext}"))

    for cf in config_files:
        with open(cf, "r") as f:
            model_cfg = json.load(f)
            if all(a in model_cfg for a in ("embed_dim", "audio_cfg", "text_cfg")):
                _MODEL_CONFIGS[cf.stem] = model_cfg

    _MODEL_CONFIGS = {
        k: v
        for k, v in sorted(_MODEL_CONFIGS.items(), key=lambda x: _natural_key(x[0]))
    }


_rescan_model_configs()  # initial populate of model config registry


def load_state_dict(checkpoint_path: str, map_location="cpu", skip_params=True):
    checkpoint = torch.load(checkpoint_path, map_location=map_location)
    if isinstance(checkpoint, dict) and "state_dict" in checkpoint:
        state_dict = checkpoint["state_dict"]
    else:
        state_dict = checkpoint
    if skip_params:
        if next(iter(state_dict.items()))[0].startswith("module"):
            state_dict = {k[7:]: v for k, v in state_dict.items()}
        
        # removing position_ids to maintain compatibility with latest transformers update        
        if version.parse(transformers.__version__) >= version.parse("4.31.0"): 
            del state_dict["text_branch.embeddings.position_ids"]
    # for k in state_dict:
    #     if k.startswith('transformer'):
    #         v = state_dict.pop(k)
    #         state_dict['text_branch.' + k[12:]] = v
    return state_dict


def create_model(
    amodel_name: str,
    tmodel_name: str,
    pretrained: str = "",
    precision: str = "fp32",
    device: torch.device = torch.device("cpu"),
    jit: bool = False,
    force_quick_gelu: bool = False,
    openai_model_cache_dir: str = os.path.expanduser("~/.cache/clip"),
    skip_params=True,
    pretrained_audio: str = "",
    pretrained_text: str = "",
    enable_fusion: bool = False,
    fusion_type: str = 'None'
    # pretrained_image: bool = False,
):
    amodel_name = amodel_name.replace(
        "/", "-"
    )  # for callers using old naming with / in ViT names
    pretrained_orig = pretrained
    pretrained = pretrained.lower()
    if pretrained == "openai":
        if amodel_name in _MODEL_CONFIGS:
            logging.info(f"Loading {amodel_name} model config.")
            model_cfg = deepcopy(_MODEL_CONFIGS[amodel_name])
        else:
            logging.error(
                f"Model config for {amodel_name} not found; available models {list_models()}."
            )
            raise RuntimeError(f"Model config for {amodel_name} not found.")

        logging.info(f"Loading pretrained ViT-B-16 text encoder from OpenAI.")
        # Hard Code in model name
        model_cfg["text_cfg"]["model_type"] = tmodel_name
        model = load_openai_model(
            "ViT-B-16",
            model_cfg,
            device=device,
            jit=jit,
            cache_dir=openai_model_cache_dir,
            enable_fusion=enable_fusion,
            fusion_type=fusion_type
        )
        # See https://discuss.pytorch.org/t/valueerror-attemting-to-unscale-fp16-gradients/81372
        if precision == "amp" or precision == "fp32":
            model = model.float()
    else:
        if amodel_name in _MODEL_CONFIGS:
            logging.info(f"Loading {amodel_name} model config.")
            model_cfg = deepcopy(_MODEL_CONFIGS[amodel_name])
        else:
            logging.error(
                f"Model config for {amodel_name} not found; available models {list_models()}."
            )
            raise RuntimeError(f"Model config for {amodel_name} not found.")

        if force_quick_gelu:
            # override for use of QuickGELU on non-OpenAI transformer models
            model_cfg["quick_gelu"] = True

        # if pretrained_image:
        #     if 'timm_amodel_name' in model_cfg.get('vision_cfg', {}):
        #         # pretrained weight loading for timm models set via vision_cfg
        #         model_cfg['vision_cfg']['timm_model_pretrained'] = True
        #     else:
        #         assert False, 'pretrained image towers currently only supported for timm models'
        model_cfg["text_cfg"]["model_type"] = tmodel_name
        model_cfg["enable_fusion"] = enable_fusion
        model_cfg["fusion_type"] = fusion_type
        model = CLAP(**model_cfg)

        if pretrained:
            checkpoint_path = ""
            url = get_pretrained_url(amodel_name, pretrained)
            if url:
                checkpoint_path = download_pretrained(url, root=openai_model_cache_dir)
            elif os.path.exists(pretrained_orig):
                checkpoint_path = pretrained_orig
            if checkpoint_path:
                logging.info(f"Loading pretrained {amodel_name}-{tmodel_name} weights ({pretrained}).")
                ckpt = load_state_dict(checkpoint_path, skip_params=True)
                model.load_state_dict(ckpt)
                param_names = [n for n, p in model.named_parameters()]
                for n in param_names:
                    print(n, "\t", "Loaded" if n in ckpt else "Unloaded")
            else:
                logging.warning(
                    f"Pretrained weights ({pretrained}) not found for model {amodel_name}."
                )
                raise RuntimeError(
                    f"Pretrained weights ({pretrained}) not found for model {amodel_name}."
                )

        if pretrained_audio:
            if amodel_name.startswith('PANN'):
                if 'Cnn14_mAP' in pretrained_audio:  # official checkpoint
                    audio_ckpt = torch.load(pretrained_audio, map_location='cpu')
                    audio_ckpt = audio_ckpt['model']
                    keys = list(audio_ckpt.keys())
                    for key in keys:
                        if 'spectrogram_extractor' not in key and 'logmel_extractor' not in key:
                            v = audio_ckpt.pop(key)
                            audio_ckpt['audio_branch.' + key] = v
                elif os.path.basename(pretrained_audio).startswith('PANN'):  # checkpoint trained via HTSAT codebase
                    audio_ckpt = torch.load(pretrained_audio, map_location='cpu')
                    audio_ckpt = audio_ckpt['state_dict']
                    keys = list(audio_ckpt.keys())
                    for key in keys:
                        if key.startswith('sed_model'):
                            v = audio_ckpt.pop(key)
                            audio_ckpt['audio_branch.' + key[10:]] = v
                elif os.path.basename(pretrained_audio).startswith('finetuned'):  # checkpoint trained via linear probe codebase
                    audio_ckpt = torch.load(pretrained_audio, map_location='cpu')
                else:
                    raise ValueError('Unknown audio checkpoint')
            elif amodel_name.startswith('HTSAT'):
                if 'HTSAT_AudioSet_Saved' in pretrained_audio:  # official checkpoint
                    audio_ckpt = torch.load(pretrained_audio, map_location='cpu')
                    audio_ckpt = audio_ckpt['state_dict']
                    keys = list(audio_ckpt.keys())
                    for key in keys:
                        if key.startswith('sed_model') and ('spectrogram_extractor' not in key
                                                            and 'logmel_extractor' not in key):
                            v = audio_ckpt.pop(key)
                            audio_ckpt['audio_branch.' + key[10:]] = v
                elif os.path.basename(pretrained_audio).startswith('HTSAT'):  # checkpoint trained via HTSAT codebase
                    audio_ckpt = torch.load(pretrained_audio, map_location='cpu')
                    audio_ckpt = audio_ckpt['state_dict']
                    keys = list(audio_ckpt.keys())
                    for key in keys:
                        if key.startswith('sed_model'):
                            v = audio_ckpt.pop(key)
                            audio_ckpt['audio_branch.' + key[10:]] = v
                elif os.path.basename(pretrained_audio).startswith('finetuned'):  # checkpoint trained via linear probe codebase
                    audio_ckpt = torch.load(pretrained_audio, map_location='cpu')
                else:
                    raise ValueError('Unknown audio checkpoint')
            else:
                raise f'this audio encoder pretrained checkpoint is not support'

            model.load_state_dict(audio_ckpt, strict=False)
            logging.info(f"Loading pretrained {amodel_name} weights ({pretrained_audio}).")
            param_names = [n for n, p in model.named_parameters()]
            for n in param_names:
                print(n, "\t", "Loaded" if n in audio_ckpt else "Unloaded")
            
        model.to(device=device)
        if precision == "fp16":
            assert device.type != "cpu"
            convert_weights_to_fp16(model)

        if jit:
            model = torch.jit.script(model)

    return model, model_cfg


def create_model_and_transforms(
    model_name: str,
    pretrained: str = "",
    precision: str = "fp32",
    device: torch.device = torch.device("cpu"),
    jit: bool = False,
    force_quick_gelu: bool = False,
    # pretrained_image: bool = False,
):
    model = create_model(
        model_name,
        pretrained,
        precision,
        device,
        jit,
        force_quick_gelu=force_quick_gelu,
        # pretrained_image=pretrained_image
    )
    preprocess_train = image_transform(model.visual.image_size, is_train=True)
    preprocess_val = image_transform(model.visual.image_size, is_train=False)
    return model, preprocess_train, preprocess_val


def list_models():
    """enumerate available model architectures based on config files"""
    return list(_MODEL_CONFIGS.keys())


def add_model_config(path):
    """add model config path or file and update registry"""
    if not isinstance(path, Path):
        path = Path(path)
    _MODEL_CONFIG_PATHS.append(path)
    _rescan_model_configs()
